Apparatus for coating electrical conductors



K. M. WATSON Sept. 8, 1931.

APPARATUS FOR COATING ELECTRICAL CONDUCTORS Filed Dec. 16, 1926 Patented Sept. 8, 1931 UNITED STATES PATENT OFFICE J KENNETH MERLE WATSON, or MADISON, 'WISQONSIN, ASSIGNOR T WESTERN ELECTRIC COMPANY, INCORPORATED, or'nnw YORK; N. Y., A CORPORATION or NEW YORK APPARATUS FOR COATING ELECTRICAL CONDUCTORS Application filed December 16, 1926. Serial No. 155,303.

' This invention relates to an apparatus for coating electrical conductors, and more particularly to an apparatus for baking a coat ing of insulating enamel upon a wire.

The primaryobject of this invention is to provide a simple and eflicient apparatus for economically and expeditiously baking a coating on electrical conductors.

In order to obtain these and other objects and in accordance with the general features of the invention, one embodiment thereof includes apparatus. for continuously passing a wire through a bath of insulating mate- 7 rial.. The wire prior to its entrance into the insulating material, is passed over a pulley which forms one terminal of a source of electrical current supply and subsequent to this coating operation, the wire is passed over a rotary member which forms the other terminal of a source of the electrical current supply. Sharp edged blades carried'by the rotary member penetrate the insulating coating and contact with the wire, thereby including an ever-changing wire portion of constant extent within an electrical circuit, the current passing therethrough serving to heat the wire and thereby bake the insulating coating. Restricted openings formed in,

the coating during the penetration of the blades completely close due tothe normal flow of the insulating coating, thus presenting a wire coating which is of a uniform and homogeneous character.

These and other objects willvbe apparent from. the following detailed description, reference being had to the acpompa'nying drawings inwhich 7 Fig. 1 is a fragmentary side elevational .view, partially in section of"a wire insulating apparatus, a circuit diagram including a source of low frequency current supply be-- ing shown in association therewith,- and Fig. 2 is an enlarged fragmentary sectional view of the rotary member taken on the line 2-2 of Fig. 1. I

Referring now to the drawings, wherein like numerals have been employed-to designate similar parts throughout the various figures,.it' will beob'served that a wire sup ply spool 10 is carried by. a bracket secured through the bath 19 the wire is directed upwardly through a heating chamber 22 and passes over a pulley or sheave 23 which is supported by the upper end of a vertical bracket 24 suitably mounted upon the upper portion of the machine frame 11. The wire is then fed downwardly from this sheave 23 to a-sheave (not shown) companion to and in alignment with the sheave 21 and then upwardly over an .idler guide pulley 25. From the, pulley 25 the wire is passed over a rotary metallic member'26 which is provided with a plurality of sharp edged blades 27 of electrical conducting material and then to a receiving spool 29 which may be'driven from any suitable source of power (not shown), the speed of the spool being regulated to the speed at which it is desired to feed the wire upwardly through a heating chamber 22.

The rotary member 26, which is slotted to receive the blades 27 and provided with perlpheral flanges 30. (Fig. 2), isnnounted' upon asuitable support 32.and is electrically member 26 'and the pulley 14 form opposite terminals-of an electrical circuit which includes asuitable source of low frequency electrical current supply 35, a switch 36, a

transformer 37, a switch 38 and an adjust-g I able resistance 39. The circuit including the secondary winding of the transformer-37 may be traced in part from a spring brush 42 engaging with a hub on the pulley 14 through the adjustable resistance 39, through" the secondary winding of the transformer 37, the switch 38, and thence to a spring connection between the rotary member 26 and the pulley 14 through the portion of the wire 13 extending therebetween. From the foregoing it will be clear that when the switches 86 and 38 are closed and the electrical circuit is completed through the wire 13 as described, current will flow therethrough and by proper adjustment of the resistance 39, the heat generated thereby within that portion of the wire may serve to effectively bake the coating of insulating enamel previously applied to that portion. In this connection it is to be understood that a plurality of sheaves similar to the sheaves 21 and 23 might be employed, the number of sheaves being dependent upon the number of times it is desired to pass the wire through the coating compound and through the chamber 22 before passing it over the blades 27. The member 26 is freely rotatable in the support 32 so that as the coated wire is drawn over the blades 27, the s eed of travel of the wire and the blades wil be the same and hence any tendency to cause a relative movement between the sharp edges of the blades and the coating through which they penetrate is positively precluded. By this construction the size of openings or incisions made in the coatings are kept within desirable restricted limits.

In some instances it is desirable to control the temperature of the coated wire 13 as it passes over and is carried into contact with the blades 27. The reason for this will be obvious when it is understood that as the wire 13 contacts with a blade 27, it is desirable to have the blade and the member 26 in which it is mounted at substantially the same temperature as the wire. Should the wire be at a much higher temperature than that of the blade, there might be a tendency for a quick transfer of heat from thewire 'to the rotary member 26 which would result in a sudden contraction of the wire and hence the possible scraping of the blade thereon. This scraping might have a tendency to enlarge the incision made by the blade, and obviously it is desirable to make the smallest possible incision in effecting the contact between the blade and the wire. In order to render possible th is temperature control a pipe 15 having a communication with a suitable source of water supply (not shown) through a valve 46 is adapted to project a stream of water or other suitable quenching medium upon the coated wire as it approaches the blades 27 and in this manner the tempera-- ture of the rotary member 26 and the wire 13 may be properly regulated.

By the use of apparatus embodying this invention an electrical heating current may be passed through successive, ever-changing portions of a coated wire of uniform length, this length being determined by the extent of wire reaching between the blades 27 and the metallic pulley 14. In the disclosure a source of low frequency current su ply 35 has been shown, but it will be un erstood that direct current could be employed with equal efi'ectiveness. The penetrations or incisions produced in the wire coating by the blades27 close up completel after the coated wire passes over the blades ue to the natural flow of the'coating compound which is used and no trace of the incisions can be distinguished. Hence a machine of the type disclosed and described renders possible the direct contact of a terminal (the blades 27) of a source of electrical current supply with a moving coated wire, one of the blades always being in contact with the conductor, thereby greatly facilitating the baking of the coating by the passage of a low frequency current through an ever-changing constant portion of the wire. Y

It is' to be understood that the invention is not limited to the exact construction and functional characteristics herein described and that the appended claims have been 160 drawn to define other modificationswhich come within the'true spirit and scope of the invention. v

What is claimed is: 1

1. In an apparatus for insulating an electrical cdnductor, means for applying a coating of insulating material to the conductor,

a source of electrical current supply associated therewith, and-means for passing a low frequency electrical heating current L10 from the source of supply through ever-- changing insulated portions of the conductor of constant extent.

2. In an apparatus for insulating an electrical conductor, means for applying a coating of insulating material to the conductor,

a source of electrical current supply associated therewith, and means for makin direct contact with a. coated portion or the conductor through the coating thereof to and cause a heating current to pass therethrough.

4. In an apparatusfor insulating an electrical conductor, means for applying a coating of insulating material to a conductor, spaced terminal members connected with a source of low frequency current supply for passing a heating current through the'conductor, one of said terminal members engaging an uncoated portion of the conductor, the other being provided with means for engaging the coated portion of the conduc tor, and means to cause a relative movement between the terminals and the conductor to continuously change the position of the conductor being heated to continuously bake the coating thereon.

5. In an apparatus for insulating an electrical conductor, means for applying a coating of insulating material to the conductor, means for making an electrical contact with an uncoated portion of the conductor, means for making an electrical contact at a plurality of spaced points with a coated portion oi the conductor, and a source of electrical energy cooperating with said contacts for constantly heating a predetermined length of the conductor.

6. In an apparatus for insulating an electrical conductor, means for applying a coating of insulating material to the conductor, means for temporarily displacing the insulating coating to make electrical contact with the conductor, and means cooperating with the last mentioned means for electrically baking the insulating coating.

In witness whereof, I hereunto subscribe my name this 26th day of November A. D,

KENNETH MERLE WATSON. 

